I've seen people complain about the current state of race transformations and how picking as many minor races as you can fit in a run is considered mandatory.
I don't necessarily agree on the mandatory side of things, but I do agree that, having 20 different minor transformations and 8 major ones, it's pretty hard from an RP perspective to fit more than 1-3 minor transformations, depending on your choice of major transformation. I do however agree that it's true that you're likely to fall behind the other empires on some aspects if you don't stack a minimum amount of minor transformations and a major one on top.
While some might say that "if you wanna RP, deal with the mechanical consequences", and in most scenarios I'd be inclined to agree, I think in AoW4 there is room to provide an entirely different route to pick from. I humbly bring you the very rough concept of:
THE TOME OF PURITY
A tier III Order/Nature tome based around the idea of giving your units buffs/enchantments that become weaker/less effective the more transformations your units have, and debuffs/traits with an increased effect the more transformations your enemy's units have.
(More details and examples below)